To meet the demanding requirements for consumer appliances, the industry is moving towards the integration of a complete system on a single chip, a so-called system-on-chip (SoC). A system-on-chip comprises multiple data processing devices. The multiple processing devices may include multiple heterogeneous processor cores and dedicated hardware peripherals. A system-on-chip typically runs several layers of software, such as: a drivers layer, an operating system layer, a streaming layer and a control layer. These layers of software are stacked upon each other and they cooperate to build a complete embedded application. System-on-chip designs can be used, e.g., for domestic and mobile appliances.
Between the processing devices many data streams are present. For example, after a first processor core has finished processing a data packet, e.g., a part of a picture, the data that results may be forwarded to a second processor core, for further processing of a different kind. The data is sent as a data stream over, e.g., a bus or a network-on-chip interconnect, etc., between the first processor core and the second processor core.
The data traffic in a data stream can be observed, i.e., measured by a monitor. The monitor may be capable of signaling that an abnormal condition is present in the data stream.
The published European patent application EP 1811415 discloses a known system comprised in a system-on-chip. The known system comprises an autonomous supervision module. The supervision module counts the data arriving in the secure system-on-chip and compares this number to a predefined maximum. An abnormal situation leads to a warning state in which the CPU can decide how to react.